Skip to content
Rival
How it worksPrivacyTerms
Explore all of Rival

Explore

  • Compare Models
  • All Models
  • Image Comparison
  • Audio Comparison
  • Image Generation
  • Best AI For...
  • Arena
  • API Pricing
  • Challenges

Discover

  • SubjectiveBench
  • Default Index
  • Research
  • Research downloads
  • Rival Kits
  • Find your AI taste
  • UI Glow-Up
  • VoiceLock
  • Cost Cutter
  • Agent skills
  • Benchmarks vs Vibes
  • Brief
  • Jailbreak
  • Model Updates
  • Provider Status
  • AI Creators

Connect

  • Methodology
  • Advertise
  • Partnerships
  • Privacy Policy
  • Terms
  • RSS Feed
  1. Home
  2. /
  3. Compare
  4. /
  5. GPT-6 LunavsSolar Pro 4
Updated Sep 2026

GPT-6 LunavsSolar Pro 4

Solar Pro 4 is cheaper than GPT-6 Luna at $0.09/M vs $0.1/M input tokens.

GPT-6 Luna and Solar Pro 4 compared across 14 shared prompts
SpecGPT-6 LunaSolar Pro 4
Input price$0.1/M tokens$0.09/M tokens
Output price$0.5/M tokens$0.36/M tokens
Context window1.1M tokens524K tokens
WeightsClosed—
Free API (OpenRouter)NoNo
ReleasedSep 2026Aug 2026
Side by side

Same prompt, both answers

Opening lines from 6 of the 14 prompts both answered. Formatting stripped, words untouched.

Simple 7-Ingredient Recipe

Create a simple recipe for a delicious dish (sweet or savory) using only 7 common pantry ingredients. Include a creative name for the dish…

GPT-6 Luna113 words
Crispy Parmesan Chickpeas A crunchy, savory snack with a cheesy finish Ingredients (7): 1 can chickpeas, drained and dried 1 tablespoon olive oil ½ teaspoon salt ½ teaspoon paprika ¼ teaspoon garlic powder ¼ cup grated Parmesan 1 tablespoon lemon juice Prep time: 5 minutes Cook time: 30–35 minutes Instructions: Heat…
Read the full answer
Solar Pro 4294 words
🍝 Golden Umami Silk Noodles A savory-sweet pasta dish that transforms basic pantry staples into a glossy, flavorful meal. It's quick, comforting, and relies on the balance of soy, honey, and butter for a rich sauce without needing fresh produce.
Read the full answer

Startup Pitch Teardown

Here's a pitch deck summary for a startup called "MindMeld AI": **Slide 1 - Vision:** "We're building the future of human-AI collaboration.…

GPT-6 Luna421 words
“94% accuracy” and “predict what you want to type before you think it” Why it’s weak: This is the deck’s central technical claim, but “accuracy” is undefined: Is it word-level or character-level accuracy, measured on a fixed vocabulary or open-ended text, and under what conditions?
Read the full answer
Solar Pro 41,009 words
Here are the three weakest claims in the MindMeld AI pitch deck, along with an analysis of why they undermine credibility and specific recommendations for improvement. The Technical Performance Claim Claim: "Our proprietary EEG headband uses advanced ML to decode neural patterns into text with 94% accuracy...
Read the full answer

Ethical Dilemma with Stakeholders

You're the CEO of a pharmaceutical company. Your best-selling drug ($2B annual revenue, used by 4 million patients for chronic pain) has…

GPT-6 Luna1,930 words
I would not wait six months for more data. A potentially fatal signal affecting a drug used by millions requires immediate safety assessment, prompt engagement with regulators, and a plan to inform patients and clinicians.
Read the full answer
Solar Pro 41,851 words
As CEO, my overriding duty is to balance patient safety, legal/regulatory compliance, fiduciary responsibility, and long-term corporate survival. A 1-in-8,000 risk of liver failure is rare but severe, potentially fatal, and materially unexpected relative to the current label.
Read the full answer

Adversarial Contract Review

Here is a contract for a software consulting engagement: --- SOFTWARE CONSULTING AGREEMENT This Agreement is entered into between TechCorp…

GPT-6 Luna2,040 words
This agreement is strongly one-sided. The enforceability of particular terms—especially the non-compete, liability provisions, and arbitration clause—depends on the governing law and the facts. The agreement does not identify a governing law, which is itself a significant gap.
Read the full answer
Solar Pro 41,382 words
Disclaimer: I am an AI assistant and not an attorney. The following analysis is for informational purposes only and does not constitute legal advice. Contract laws vary significantly by jurisdiction (e.g., state, country).
Read the full answer

Beginner's Longevity Plan

Outline a simple, actionable 1-month plan for someone starting their journey towards better health and longevity. Focus on 3 key areas…

GPT-6 Luna330 words
A simple 1-month starter plan Choose three foundations: food, movement, and sleep. Aim for steady habits, not perfection. If you have a health condition, significant pain, or concerns about changing your activity or diet, check with a healthcare professional first.
Read the full answer
Solar Pro 4859 words
Here’s a simple, progressive 1-month plan built around Diet, Exercise, and Sleep. Each week adds one small, beginner-friendly shift to each area. The goal isn’t perfection; it’s building consistent, sustainable habits that compound over time.
Read the full answer

Debug This Architecture

Here's the architecture for a real-time collaborative document editor (like Google Docs): **System Overview:** - Frontend: React SPA with…

GPT-6 Luna1,979 words
The main architectural risk is that the system treats collaborative editing as “write a value, then broadcast it.” That works poorly under concurrency, server failures, reconnects, and scale.
Read the full answer
Solar Pro 41,598 words
This architecture contains several fundamental mismatches between real-time collaborative editing requirements and the chosen patterns. Below is a systematic breakdown of failure modes, race conditions, and scaling bottlenecks, each with a targeted solution and explicit trade-offs.
Read the full answer
Our Verdict
GPT-6 Luna
GPT-6 Luna
Solar Pro 4
Solar Pro 4Runner-up

Not enough votes to call it. On the specs, GPT-6 Luna has the edge: newer, bigger context window, major provider backing.

Too close to call
API pricing

Cost per 1M tokens

GPT-6 Luna
Input
$0.10
Output
$0.50
Solar Pro 4
Input
$0.09
1.1× cheaper
Output
$0.36
1.4× cheaper

Solar Pro 4 is cheaper on both: 1.1× input, 1.4× output.

Where to run it

4 hosts, cheapest first

GPT-6 Luna3 hosts
HostInOutContextUptime
Azure AI Foundry$0.10 in·$0.50 out·1.1M·88.4% upOpenAI$0.10 in·$0.50 out·1.1M·99.9% upAmazon Bedrock$0.11 in·$0.55 out·1.1M·99.8% up
Solar Pro 41 host
HostInOutContextUptime
UUpstage$0.09 in·$0.36 out·524k·99.8% up

Per million tokens. Prices and uptime via OpenRouter, checked 25 Sep 2026.

Research

What we learned reading every model

FAQ

Common questions

GPT-6 Luna is developed by OpenAI while Solar Pro 4 is developed by Upstage. GPT-6 Luna has a 1.1M token context window vs Solar Pro 4's 524K. You can compare their actual outputs across 14 challenges on Rival to see how they differ in practice.

It depends on your use case. GPT-6 Luna and Solar Pro 4 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 14 challenges so you can judge which fits your needs best.

GPT-6 Luna costs $0.1/M input tokens and Solar Pro 4 costs $0.09/M input tokens. Solar Pro 4 is $0.01/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.

This page shows a side-by-side comparison of GPT-6 Luna and Solar Pro 4 across shared challenges. You can vote on which model produced the better output in a blind duel. Browsing and voting are free. No account is needed to look; signing in only saves your votes and likes.

Keep exploring

More comparisons

Against the newest arrivals

GPT-6 Luna logoSolar Mini 4 logo
GPT-6 Luna vs Solar Mini 4Landed Sep 2026
Solar Pro 4 logoQwen3.8 Max Prime logo
Solar Pro 4 vs Qwen3.8 Max PrimeLanded Sep 2026
GPT-6 Luna logoGLM 5.3 Prime logo
GPT-6 Luna vs GLM 5.3 PrimeLanded Sep 2026
Solar Pro 4 logoQwen3.8 Omni Flash logo
Solar Pro 4 vs Qwen3.8 Omni FlashLanded Sep 2026
GPT-6 Luna logoCommand A+ logo
GPT-6 Luna vs Command A+Landed Sep 2026
Solar Pro 4 logoClaude Opus 5.5 logo
Solar Pro 4 vs Claude Opus 5.5Landed Sep 2026
GPT-6 Luna logoGPT-6 Luna Pro logo
GPT-6 Luna vs GPT-6 Luna ProLanded Sep 2026
Solar Pro 4 logoGPT-6 Sol Pro logo
Solar Pro 4 vs GPT-6 Sol ProLanded Sep 2026

Same lab, same size, long tail

GPT-6 Luna logoGPT-6 Sol Pro logo
GPT-6 Luna vs GPT-6 Sol ProSame lab
GPT-6 Luna logoGPT-6 Sol logo
GPT-6 Luna vs GPT-6 SolSame lab
Solar Pro 4 logoSolar Mini 4 logo
Solar Pro 4 vs Solar Mini 4Same lab
Solar Pro 4 logoSolar Pro 3 logo
Solar Pro 4 vs Solar Pro 3Same lab
Solar Pro 4 logoDeepSeek R1 logo
Solar Pro 4 vs DeepSeek R1Same size
Solar Pro 4 logoDeepSeek R1 0528 logo
Solar Pro 4 vs DeepSeek R1 0528New provider
Solar Pro 4 logoDeepSeek V3 (March 2024) logo
Solar Pro 4 vs DeepSeek V3 (March 2024)New provider
Solar Pro 4 logoDeepSeek V3.2 logo
Solar Pro 4 vs DeepSeek V3.2Same size

Model pages

GPT-6 Luna logo
GPT-6 Luna20 outputs, specs and price
Solar Pro 4 logo
Solar Pro 414 outputs, specs and price
Rival
How it worksPrivacyTerms
Explore all of Rival

Explore

  • Compare Models
  • All Models
  • Image Comparison
  • Audio Comparison
  • Image Generation
  • Best AI For...
  • Arena
  • API Pricing
  • Challenges

Discover

  • SubjectiveBench
  • Default Index
  • Research
  • Research downloads
  • Rival Kits
  • Find your AI taste
  • UI Glow-Up
  • VoiceLock
  • Cost Cutter
  • Agent skills
  • Benchmarks vs Vibes
  • Brief
  • Jailbreak
  • Model Updates
  • Provider Status
  • AI Creators

Connect

  • Methodology
  • Advertise
  • Partnerships
  • Privacy Policy
  • Terms
  • RSS Feed